package main

import "fmt"

func f1(n int) int {
	n = 10
	return n
}

func f2(n *int) int {
	*n = 20
	return *n

}

func f3(n int) {
	n = 100
}
func main() {

	a := 1
	fmt.Println(f1(a)) //10

	f3(10)
	fmt.Println(a) //1

	b := f2(&a)
	fmt.Println(b) // 20
}
